Heel-holding device for safety ski bindings

ABSTRACT

A carrying member for a soleholder is biased by a spring. A heel-holding device is adapted to automatically assume a locking position in response to the introduction of a skiing boot and to be opened arbitrarily, for example, by the application of a slight pressure with the ski pole on a release member, or automatically in response to an excessive tensile force acting substantially in an upward vertical direction. The carrying member forms a coupler link of a four-bar linkage, which has two cranks of equal length, to which the carrying member is pivotally connected and which are pivoted in a housing on horizontal transverse axes spaced the same distance apart as the pivotal axes of the carrying member. The transverse axes lie in the housing in an approximately horizontal plane. The spring acts on the carrying member by the crank which is remote from the soleholder. The pivot connecting the carrying member to that crank forms also the pivot for the carrying member during a second phase of movement, the second phase serves to open the device and succeeds a first phase of movement, in which the carrying member moves parallel to itself.

United States Patent [72] Inventors Hannes Marker Garmisch-Partenkirchen;

Ludwig Axthammer, Schweinfurt/Main,

- both of Germany [21] Appl. No. 862,880 [22] Filed Oct. 1, I969 [45] Patented Oct. 12, 1971 [73] Assignee Hannes Marker Garmisch-Partenkirchen, Germany [32] Priority Oct. 1, 1968 [3 3] Germany [31] P18 00 397.9

[54] HEEL-HOLDING DEVICE FOR SAFETY SKI BINDINGS 13 Claims, 5 Drawing Figs.

[52] [1.8. CI ..280/1 1.35 T [51] Int. Cl A63c 9/00 [50] Field of Search ..280/11.35 T

[56] References Cited UNITED STATES PATENTS 3,125,349 3/1964 Schweizer 280/1 1.35 3,333,859 8/1967 Smolka et a1. 280]! 1.35

FOREIGN PATENTS 752,739 2/1967 Canada 280/1 1.35

1,503,066 1967 France 280/1 1.35

1,498,203 1967 France 462,015 1967 Switzerland ABSTRACT: A carrying member for a soleholder is biased by a spring. A heel-holding device is adapted to automatically assume a locking position in response to the introduction of a skiing boot and to be opened arbitrarily, for example, by the application of a slight pressure with the ski pole on a release member, or automatically in response to an excessive tensile force acting substantially in an upward vertical direction. The carrying member forms a coupler link of a four-bar linkage, which has two cranks of equal length, to which the carrying member is pivotally connected and which are pivoted in a housing on horizontal transverse axes spaced the same distance apart as the pivotal axes of the carrying member. The transverse axes lie in the housing in an approximately horizontal plane. The spring acts on the carrying member by the crank which is remote from the soleholder. The pivot connecting the carrying member to that crank forms also the pivot for the carrying member during a second phase of movement, the second phase serves to open the device and succeeds a first phase of movement, in which the carrying member moves parallel to itself.

HEEL-HOLDING DEVICE FOR SAFETY SKI BINDINGS The present invention relates to a heel-holding device for safety ski bindings, which device comprises a carrying member for a soleholder, which carrying member is biased by a spring, said device being adapted to automatically assume its locking position in response to the introduction of a skiing boot, and to be opened arbitrarily, for example, by the application of a slight pressure with the ski pole on a release member, or automatically in response to an excessive tensile force acting substantially in an upward vertical direction. The carrying member forms a coupler link of a four-bar linkage, which has two cranks of equal length, to which the carrying member is pivotally connected and which are pivoted in a housing on horizontal transverse axes spaced the same distance apart as the pivotal axes of the carrying member.

In a known heel-holding device of that type, the carrying member for the soleholder carries also a closing pedal, the two cranks lie one over the other and are slightly downwardly inclined toward the soleholder. The upper crank is under the influence of a spring which tends to oppose a force acting on the soleholder in the releasing sense, whereas the lower crank is under the influence of a weak retaining spring, which holds the carrying member of the soleholder in a position to receive the' boot when the device is unlocked.

Compared to other known heel-holding devices, that known heel-holding device has the disadvantage that the soleholder will not move away from the heel immediately when the heel is lifted by a force acting in the releasing sense. Hence there is no free slipping of the boot out of the binding, and thereby resulting in excessive wear to the boot. The heel-holding device which has just been discussed has still other disadvantages which reduce its utility. The device is locked by a detent device so that forces which act on the soleholder, e.g. as a result of shocks encountered during skiing, and which do not result in a release, must be taken up immediately and entirely by the leg of the skier and cannot be taken up elastically by the device. This may result in undesirable strains and to premature fatigue in the skies.

It is an object of the present invention so to design and improve a heel-holding device so that the disadvantages of the known devices are avoided in a simple manner.

This invention relates to a heel-holding device for safety ski bindings, which device comprises a carrying member for a soleholder, which carrying member is biased by a spring, and which device is adapted to automatically assume its lacking position response to the introduction of the skiing boot and to be opened arbitrarily, for example, by the application of slight pressure with the ski pole on a release member, or automatically in response to an excessive tensile force acting in a substantially upward vertical direction. The carrying member forming a coupler link of a four-bar linkage, has two cranks of equal length, to which the carrying member is pivotally connected and which are pivoted in a housing on horizontal transverse axes spaced the same distance apart as the pivotal axes on the carrying member. According to the invention the transverse axes in the housing lie in an approximately horizontal plane, the spring acts on the carrying member, housing lie in an approximately horizontal plane, the spring acts on the carrying member by the crank which is remote from the soleholder, and the pivot connecting the carrying member to that crank forms also the pivot for the carrying member during a second phase of movement. Such second phase serves to open the device and succeeds a first phase of movement, in which the carrying member moves parallel to itself.

The provision of a second phase of movement, which begins when the two cranks lie one behind the other in a plane, and in which the four-bar linkage acts virtually as a single rocker lever, permits a simplification of the design and affords the advantages that the manufacture is simple and the liability that the device will be deranged is minimized. Because the spring acts on a crank of the four-bar linkage directly without a sliding member being interposed, the device can elastically take up harmless shocks.

The design will be improved if the crank which is remote from the soleholder consists of one arm of a bellcrank lever and the spring acts on the other arm of said lever. This arrangement results in a low, extended design.

In the preferred embodiment of the invention, one end of the spring can be held to a part which is fixed to the housing and is adjustable to change the initial stress of the spring. The force required for a release can also be varied by change of the pointwhere the spring acts on the crank.

An arrangement has proved desirable in which the spring consisting of a helical compression spring is approximately horizontal and is mounted in the housing on an axis which extends in the longitudinal direction of the ski, the spring extends away from the soleholder beyond the crank, a cage is provided to accommodate the pressure-exerting end of the spring and the spring cage is coupled to the long link at least when the device is in its locked position. With this arrangement, optimum values can be selected as to the length of the spring and the spring constant. In a development of the inven tion it will be desirable if the spring cage bears on the housing when the heel holding device is in its locked position and in the position assumed by it after an arbitrary release. The spring cage may be mounted in the housing for a pivotal move ment about a horizontal transverse axis.

For an arbitrary opening of the heel-holding device, an actuating handle is desirably provided which serves to disconnect the spring cage from the crank. The actuating handle consists suitably of a pivoted lever, which is mounted in the housing on the same axis as the crank that is remote from the soleholder.

To provide a heel-holding device which is small and compact, the spring may be fitted on a screw, which is rotatably and axially nondisplaceably mounted in the housing and which carries a nut held against rotation in the housing and on which one end of the spring is held. The nut may carry a pointer, which during a displacement of the nut moves in the housing along a scale provided in the housing so that the force required for a release of the device is indicated.

If the heel-holding device is to be adjustable to skiing boots having different lengths and to urge the skiing boot elastically against a toe iron, the housing will be mounted for displacement in the longitudinal direction of the ski on a baseplate that is fixed to the ski, with a spring interposed between the housing a baseplate.

It is also common to provide the carrying member for the soleholder with a closing pedal. Such relatively narrow pedal will adversely affect the stability of the skiing boot on the ski, unless special measures are adopted. In a special embodiment of the heel-holding device according to the invention, a high stability can be obtained without need for special lens-shaped boot abutments or like means laterally of the pedal if a closing lever is provided, which has a free end portion forming a pedal and which is pivoted in a known manner'in the housing on a horizontal transverse axis, and the closing lever is longitudinally displaceably mounted in a bearing provided in the carrying member for the soleholder. When the pedal in such arrangement is no longer required, as when the four-bar linkage has been moved beyond its neutral point, the pedal will be retracted as a result of a corresponding design of the kinematic system so that the heel of the boot rests fully on the ski or a supporting plate provided on the ski. The closing lever is preferably mounted in the housing on the same axis as the crank which is nearest to the soleholder so that there is no need for an additional pivot in the housing.

An embodiment of the invention will now be described more fully and by way of example with reference to the accompanying drawings, in which FIG. 1 is a diagrammatic view showing the heel-holding device in a closed position,

FIG. 2 shows the heel-holding device according to FIG. 1 in a position immediately before it is opened automatically,

FIG. 3 shows the heel-holding device which has been automatically opened,

FIG. 4 shows the heel-holding device immediately before it is opened arbitrarily, and

H0. 5 shows the heel-holding device when it has been opened arbitrarily.

The heel-holding device which is shown in the drawing comprises a housing 1, which is adapted to be fixed indirectly or directly to the ski, depending on whether or not the heel-holding device cooperates with a toe iron, which in normal operation condition is displaceable against a spring force in the iongitudinal direction of the ski so that the required contact pressure is applied by the skiing boot. Because this is not essential for the present invention, a design in which the housing 1 is directly connected to the ski, for example, by screws, is shown in the drawing in order to simplify the presentation and description. If the sole of the boot is to exert an elastic contact pressure on the toe iron, the housing may be mounted for displacement in the longitudinal direction of the ski to a baseplate that is secured to the ski. A spring is interposed between the housing and the baseplate. The use of a housing which is displaceable on a baseplate is also desirable to enable an adaptation to boots having different lengths.

The housing 1 comprises two horizontal pivots 2, 3, which extend transversely to the longitudinal direction of the ski and form the stationary pivots of a four-bar linkage. The coupler link 4 of that linkage forms a carrying member for a soleholder 5. To enable an adaptation to soles having different thicknesses, the soleholder may be vertically adjustable by known means, which are not shown. The carrying member 4 forming the coupler link of a four-bar linkage is pivoted by pivots 6, 7 to cranks 8, 9. The crank 8 is pivoted to the housing 1 on the pivot 3. The two cranks 8, 9 have the same length and the distances between the axes of the pivots 2, 3 and 6, 7 are the same.

The transverse axes defined by the pivots 2, 3 in the housing 1 lie in a horizontal plane. In the locked position of the device, see FIG. 1, the cranks 8, 9 are positioned downwardly and forwardly inclined from the pivots 2, 3. The crank 9 is formed by one arm of a bellcrank lever, which has another arm 10. The lever arm 10 has a fork-shaped free end portion, to which a spring cage 11 is detachably connected by two coupling pins 13. The spring cage 11 is U-shaped and embraces that end portion of a helical compression spring 12 which is on the right in the drawing. The helical compression spring 12 bears at one end on a crosspiece 14 of the spring cage 11 and at its other end bears on a spring abutment 15. The latter is connected to a nut 16, which is held against rotation and in screwthreaded engagement with a screw 17, which is rotatably and axially nondisplaceably mounted in the housing 16. When the screw extending in the longitudinal direction of the housing is rotated by a handle 18 which is carried by the screw at its end protruding from the housing, the nut 16 and with it the spring abutment can move in the longitudinal direction of the housing so that the initial stress of the helical expression spring 12 can be varied.

A closing lever 20 is mounted in the pivot 2 carried by the housing 1. The free end portion of the closing lever 20 forms a pedal. The closing lever is longitudinally displaceably mounted in a bearing 22 provided in the carrying member 4 for the soleholder.

The rear wall of the housing 1 is provided with a depression 23, which receives an extension 24 of the crosspiece 14 of the spring cage 11.

A push pin 25 is mounted in the housing 1 near the rear end thereof and is operable against the force of a weak return spring 26 and intended to cooperate with the spring cage 11.

F IG. 3 shows the heel-holding device when it has been automatically opened. As a skiing boot is inserted into the binding, the heel shown in dash-dot lines at 27 in FIGS. 1, 2 and 4 bears on the pedal 21 so that the closing lever 20 is pivotally moved about the pivot 2 and carries with the carrying member 4 and the soleholder 5. As has been stated hereinbefore, FIG. 3 shows the heel-holding device when it has been automatically opened. In this position of the device, the helical compression spring 12 is stressed almost to the force required for a release. As the carrying member 4 fonning the coupler link of the four-bar linkage is pivotally moved about the pivot 7 carried by the pivoted arm 9, the latter is moved against the force of the helical compression spring 12 into the horizontal plane which contains the two transverse axes defined by the pivots 2, 3. The crank 8 has moved into that plane at the same time so that the carrying member 4 is now moved parallel to itself. The position assumed between the two phases of movement of the carrying member 4 is shown in FIG. 2. As the pedal 21 is depressed further, the helical compression spring 12 acts in the closing sense on the carrying member 4 and the soleholder 5. The kinematic system is designed so that the pedal moves away from under the heel so that the heel rests fully on the ski when the device is in the locking position shown in FIG. I. The heel-holding device is now ready for use.

When the skier desires to step out of the binding, the heelholding device is opened arbitrarily, for example, in that pressure is applied to the pin 25, by means of a ski pole (see FIG. 4). This results in a pivotal movement of the spring cage 11 about the outside edge of the extension 24, which lies in the depression 23. This pivotal movement is opposed by a relatively small force of the helical compression spring 12. The pivotal movement of the spring cage 11 disengages its coupling pins 13 from the arm 10 of the bellcrank lever 9,10. That arm 10 is provided in each fork prong with a depression for receiving the respective coupling pin. The heel 27 can now be lifted so that the soleholder causes a pivotal movement of the four-bar linkage to its release position, shown in FIG. 5. This movement is not opposed by the force of the helical compression spring 12. The arm 10 of the bellcrank lever has at least at the free end of one fork prong a rearwardly angled extension 28, which forms a runup cam for a coupling pin 13. The helical compression spring 12 acts through the spring cage 11 and the extension 28 on the four-bar linkage to hold the same in its open position so that a separate retaining is not required. When the pressure on the pin 25 decreases, the latter is returned to its rest position by the return spring 26.

The stepping into the binding when the heel-holding device has been opened arbitrarily is performed as has been described with reference to FIG. 3 because the four-bar linkage has assumed the same position. Different from the automatic opening, the helical compression spring 12 is only slightly stressed beyond its initial stress by the pivotal movement of the spring cage 11. As is apparent from FIGS. 1, 4, and 5, the initial stress of the helical compression spring 12 causes the spring cage 11 to be urged against the rear wall of the housing 1 when the heel-holding device is closed and when it has been arbitrarily opened. It has been stated hereinbefore that that initial stress of spring 11 can be varied by a rotation of the handle 18 to displace the spring abutment 15 in the longitudinal direction of the device. A horizontal longitudinal slot may be provided in a sidewall of the housing in register with the spring abutment and a pin may be connected to the spring abutment and extend into the slot. On a scale extending along one side of the slot, that pin indicates the force required for a release of the device.

If the soleholder 5 is subjected during skiing to a tensile force acting in a substantially upward vertical direction and exceeds the initial stress of the helical compression spring 12, the soleholder can move upwardly parallel to itself against the force of the spring and can carry the carrying member 4 along. The two cranks 8, 9 are pivotally moved at the same time about the pivots 2, 3 which are fixed to the housing. Upon a decrease of the force acting on the soleholder, the spring forces the carrying member 4 and the soleholder 5 back to its initial position. If the carrying member 4 is moved under the action of a sufficiently large sustained force acting on the soleholder 5 so that the carrying member and the two cranks 8, 9 lie in a plane (see FIG. 2), the binding will then be opened because the carrying member 4 continues its pivotal movement about the pivot 7 while being positively constrained by the crank 8 whereas the crank 9 is somewhat restored by the helical compression spring and thus acts on the carrying member in the opening sense until the position shown in FIG. 3 has been reached. Hence, a resistance opposing the lifting of the heel is presented only until the predetermined release position has been reached and that resistance suddenly collapses in the release position so that the heel is reliably released by the device before the force has reached a value which is dangerous to the leg of the skier.

The heel-holding device described immediately above may be modified in that the return spring 26 and pusher pin 25 can be eliminated and replaced by pivoted lever mounted on the pivot 3 in the housing and bearing on the spring cage 11 such an alternate arrangement would serve as an operating handle for an arbitrary opening of the device. The pivoted lever and the spring cage can then be restored simultaneously under the action of the helical compression spring 12.

What is claimed is:

l; A heel-holding device particularly for safety ski bindings, which device comprises: a housing; a soleholder mounted on said housing; first and second crank bars of equal length pivotally connected to said housing on horizontal transverse crank bars, the distance between the respective pivotal connections of said carrying member and said crank bars being equal to the distance between said horizontal transverse axes; biasing means associated with said carrying member and providing a biasing force therefor; wherein said transverse axes lie in a substantially horizontal plane; wherein said biasing means acts on the carrying member through said first crank bar; wherein the pivotal connection of the carrying member and said first crank bar defines a pivot for the carrying member during a second phase of movement thereof; wherein a first phase of movement of the carrying member is of such a nature that each region thereof remains parallel to itself; and wherein said second phase of movement succeeds the first phase and serves to open the heel-holding device.

2. A heel-holding device according to claim 14, wherein said first crank bar consists of one arm of a bellcrank lever and wherein said biasing means acts on the other arm of said lever.

3. A heel-holding device according to claim 14, wherein one end of the biasing means is held at an abutment which is fixed to the housing and is adjustable for varying the initial stress of the biasing means.

4. A heel-holding device according to claim 3, wherein said biasing means is fitted on a screw rotatably and axially nondisplaceably mounted in the housing and carrying a nut held against rotation in the housing, and wherein one end of the biasing means is held at the nut.

5. A heel-holding device according to claim 4, wherein the nut carries a pointer, which during a displacement of the nut moves in the housing along a scale provided on the housing.

6. A heel-holding device according to claim I, wherein said biasing means is in the form of a helical compression spring oriented approximately horizontal and mounted in the housing of an axis which extends in the longitudinal direction of the ski, wherein the spring extends away from the soleholder beyond the crank bars, further comprising a cage for accommodating the pressure-exerting end of the spring, and wherein the spring cage is coupled to the second crank bar at least when the heel-holding device is in its locked position.

7. A heel-holding device according to claim 1, wherein the spring cage bears on the housing when the heel-holding device is in its locked position and when it has been arbitrarily un locked.

8. A heel-holding device according to claim 7, wherein the spring cage is pivotally mounted in the housing on a horizontal transverse depression.

9. A heel-holding device according to claim 7 and further comprising an actuating handle serving to disconnect the spring cage from said first crank bar.

10. A heel-holding device according to claim 9, wherein the actuating handle consists of a pivoted lever, which is mounted in the housing on the same axis as is mounted said first crank 11. A heel-holding device according to claim 1, wherein the housing is held for displacement in the longitudinal direction of the ski on a baseplate fixed to the ski and wherein a spring is interposed between the housing and the baseplate.

12. A heel-holding device according to claim I, and further comprising a closing lever having a free end portion which forms a pedal, wherein said closing lever is pivoted in the housing on a horizontaltransverse axis and wherein the closing lever is longitudinally slidably mounted in a bearing provided on the carrying member for the soleholder.

13. A heel-holding device according to claim 12, wherein the closing lever is mounted in the housing on the first axis as the crank bar. 

1. A heel-holding device particularly for safety ski bindings, which device comprises: a housinG; a soleholder mounted on said housing; first and second crank bars of equal length pivotally connected to said housing on horizontal transverse crank bars, the distance between the respective pivotal connections of said carrying member and said crank bars being equal to the distance between said horizontal transverse axes; biasing means associated with said carrying member and providing a biasing force therefor; wherein said transverse axes lie in a substantially horizontal plane; wherein said biasing means acts on the carrying member through said first crank bar; wherein the pivotal connection of the carrying member and said first crank bar defines a pivot for the carrying member during a second phase of movement thereof; wherein a first phase of movement of the carrying member is of such a nature that each region thereof remains parallel to itself; and wherein said second phase of movement succeeds the first phase and serves to open the heel-holding device.
 2. A heel-holding device according to claim 14, wherein said first crank bar consists of one arm of a bellcrank lever and wherein said biasing means acts on the other arm of said lever.
 3. A heel-holding device according to claim 14, wherein one end of the biasing means is held at an abutment which is fixed to the housing and is adjustable for varying the initial stress of the biasing means.
 4. A heel-holding device according to claim 3, wherein said biasing means is fitted on a screw rotatably and axially nondisplaceably mounted in the housing and carrying a nut held against rotation in the housing, and wherein one end of the biasing means is held at the nut.
 5. A heel-holding device according to claim 4, wherein the nut carries a pointer, which during a displacement of the nut moves in the housing along a scale provided on the housing.
 6. A heel-holding device according to claim 1, wherein said biasing means is in the form of a helical compression spring oriented approximately horizontal and mounted in the housing of an axis which extends in the longitudinal direction of the ski, wherein the spring extends away from the soleholder beyond the crank bars, further comprising a cage for accommodating the pressure-exerting end of the spring, and wherein the spring cage is coupled to the second crank bar at least when the heel-holding device is in its locked position.
 7. A heel-holding device according to claim 1, wherein the spring cage bears on the housing when the heel-holding device is in its locked position and when it has been arbitrarily unlocked.
 8. A heel-holding device according to claim 7, wherein the spring cage is pivotally mounted in the housing on a horizontal transverse depression.
 9. A heel-holding device according to claim 7 and further comprising an actuating handle serving to disconnect the spring cage from said first crank bar.
 10. A heel-holding device according to claim 9, wherein the actuating handle consists of a pivoted lever, which is mounted in the housing on the same axis as is mounted said first crank bar.
 11. A heel-holding device according to claim 1, wherein the housing is held for displacement in the longitudinal direction of the ski on a baseplate fixed to the ski and wherein a spring is interposed between the housing and the baseplate.
 12. A heel-holding device according to claim 1, and further comprising a closing lever having a free end portion which forms a pedal, wherein said closing lever is pivoted in the housing on a horizontal transverse axis and wherein the closing lever is longitudinally slidably mounted in a bearing provided on the carrying member for the soleholder.
 13. A heel-holding device according to claim 12, wherein the closing lever is mounted in the housing on the first axis as the crank bar. 